Bare-bulb Upper-Room Germicidal Ultraviolet-C (GUV) Indoor Air Disinfection for COVID-19†

Abstract

Reliable indoor air disinfection could make clinical and other necessary indoor spaces safer during epidemics with airborne transmission like COVID-19. Low-dose upper-room germicidal ultraviolet-C (GUV 254 nm) is well suited for this because of the SARS-CoV-2 virus' sensitivity to GUV inactivation and GUV's relatively easy adaptability to many types of indoor spaces without respect to outside weather conditions. However, most existing upper-room GUV fixtures are relatively expensive and inefficient at creating an upper-room disinfection zone due to loss of disinfecting UV-C photons caused by the casing and louvers designed to protect persons in the occupied space. Presented herein are two moderate-size restaurant spaces, 900 ft2 (83.6 m2) and 630 ft2 (58.5 m2), respectively, in which low-cost bare-bulb GUV fixtures, without exterior casing, were installed with upward-pulling ceiling fans to provide upper-room disinfection and lower-room safety. Proper safety-tested installations like these are adaptable to hospital emergency department waiting rooms, clinics, nursing home and prison common areas, public libraries, schools and restaurants.